Finding the Fourth Proportional to 61.38, 91.89 and 42.05

Step by Step Solution

1. Step 1: Write the proportion equation
   61.38 : 91.89 = 42.05 : x
2. Step 2: Convert to fraction form
   61.38/91.89 = 42.05/x
3. Step 3: Cross multiply
   61.38x = 91.89 × 42.05
4. Step 4: Simplify right side
   61.38x = 3,864.20
5. Step 5: Solve for x
   x = 3,864.20/61.38
6. Step 6: Final answer
   x = 62.96